MON-157 The Effect of Exogenous Cushing’s Syndrome on All-Cause and Cause-Specific Mortality: A Systematic Review

Chronic oral glucocorticoid (GC) exposure from therapeutic anti-inflammatory or immunosuppressive use is the most common cause of Cushing’s syndrome (CS). Previous studies of glucocorticoid therapy and mortality have produced inconsistent results and systematic reviews have only focused on endogenous CS. This is the first study that aimed to investigate all-cause and cause-specific mortality in association with exogenous CS from chronic oral GC therapy. The protocol was designed according to the principles of the PRISMA statement and registered in PROSPERO reference CRD42017067530. A literature review was performed in PubMed/MEDLINE (1966 to 31 Mar 2019), EMBASE (1974 to 31 Mar 2019), web of science (1900 to 31 Mar 2019), CINAHL (1981 to 31 Mar 2019) and reference lists within selected articles. Of 104,064 studies, 127 met the inclusion criteria, encompassing 51,380 patients. The Risk Of Bias In Non-randomized Studies of Interventions (ROBIN-I) tool was chosen and modified for evaluation of quality. The weighted percentage mortality by 5 groups of diseases including vasculitis, connective tissue diseases, inflammatory diseases, haematologic diseases and respiratory tract diseases, was 18.1, 12.7, 16.1, 28.2 and 5.7, respectively. The leading causes of death were cardiovascular disease (25.6%), malignancy (15.6 %), infection (13.4) and respiratory failure (10.8%). Although these studies showed high mortality in patients exposed to GC, estimates were not adjusted for known confounders and available data do not allow disentangling the relative contribution of CS vs. the underlying disease or non-GC immunosuppressive therapies. More extensive, high quality, prospective studies are needed to evaluate these associations and to identify modifiable risk factors.